Segmental readout device

ABSTRACT

A segmental readout device of the digital or alphanumeric type comprising an assembly of a plurality of closely spaced elongated electromagnetic coils, each having a core of ferrous metal, and in which the display elements comprise cylindrical magnet segments each provided with a surface character to be displayed or exhibited, magnetization of each electromagnet being effective to polarize its core to effect a bodily movement and a rotation of its related magnet segment between character exhibiting and non-exhibiting positions. A specially structured arrangement is devised for providing return magnetic flux paths to eliminate strays in the magnetic interaction between the separate magnet segments and their cores that is the cause of false displays taking place.

United States Paten Skroblsch 1 June 6, 1972 SEGMENTAL READOUT DEVICE{72] Inventor: Skrobisch, Huntington Station, jzmi fgzzggfiimi y [73]Assignee: Allard Instrument Corp., Westbury L. l., ABSTRACT A segmentalreadout device of the digital or alphanumeric [22] Filed: Nov. 14, 1969type comprising an assembly of a plurality of closely spaced elongatedelectromagnetic coils, each having a core of ferrous [21] App]. No.:876,763 metal, and in which the display elements comprise cylindricalmagnet segments each provided with a surface character to be 521 U.S. Cl..340/378, 340/381 displayed exhibited magnetizafi each electwmagne 51 11m. Cl. ..G09i' 1 1 02 being effective f is we effect bdily [58] Fieldof Search ..340/336, 366, 381, 378, 373 and a math" magnet segmentbetween character exhibiting and non-exhibiting positions. A specially[56] Referenm Cited structured arrangement is devised for providingreturn magnetic flux paths to eliminate strays in the magneticinteraction UNlTED STATES PATENTS between the separate magnet segmentsand their cores that is v the cause of false displays taking place.1124,943 2/1961 Skrobisch ..340/38l X 3,487,403 12/1969 Pihl ..340/381 X5 Claims, 10 Drawing Figures PATENTEQJUH' staff SHEET 10F 2 SEGMENTALREADQUT DEVICE This invention relates to a segmental readout device'andmore particularly to a readout device of the digital or alphanumerictype in which magnetic segments are employed as the segmental readoutdisplay elements.

In my US. Pat. No. 3,096,594 patented July 9, 1963, there is disclosed asegmental readout device in which magnetic segments are employed as partof the readout exhibiting or display elements. In that patent, thereadout elements are made to comprise narrow elongated white flapsarcuately movable between exposed display and concealed positions, eachattached to and movable with a small-diametered permanent rotor; andeach readout element is associated with a stationary elongatedelectromagnet coil located behind the rotor having a magnetizable core,said core when magnetized having two spaced poles of like polarity and asingle pole of opposite polarity, said poles being so disposed relativeto the poles of the magnet rotor that when the electromagnet isenergized the rotor rotates no more than 90 to move the readout flapbetween its exposed and concealed positions The readout device of mypresent invention relates to improvements in the readout device of mysaid patent in which the following objects are accomplished:

1. The readout exhibiting or display elements in digital oralpha-numeric display are themselves simplified in structure andoperation to comprise cylindrical magnet segments pro vided with surfacecharacters to be displayed or exhibited, each mounted for free rotationabout its longitudinal axis at an end of each electromagnet core and forbodily movement to and from said core;

2. Such a readout device of small compass in which the elongatedelectromagnetic coils are closely spaced and the associated magnetsegments are arranged to form an array of character exhibiting elementsin, for example, a seven segment digital array in which the elementsdefine the numeral or figure 8, and in which return magnetic flux pathsfor the magnet segments and cores are provided arranged in such a manneras to eliminate the strays in the magnetic interaction between theseparate magnet elements and cores that is the cause of false displays;and

3. A readout device of this described character in which the elementsprovided for the return magnetic flux paths are located in the areas ofthe central spaces i.e., within the two rectangles of the numeral orfigure 8 array, each of the two return magnetic paths serving as acommon return path for all the magnetic segments encompassing a centralspace or rectangle.

To the accomplishment of the foregoing objects and such other objects asmay hereinafter appear, my invention relates to the segmental readoutdevice as more particularly defined in the appended claims takentogether with the following specification and the accompanying drawingsin which:

FIG. 1 is a perspective view of the encased readout device of thepresent invention showing how the same is used for a digital device,with a part of the case broken away;

FIG. 2 is a front view of the readout device of FIG. I removed from thecase drawn to a slightly enlarged scale and depicting the same with themagnetic segments removed from elongated openings in which they arenormally mounted;

FIG. 3 is a view of the readout device taken in section in the plane ofthe line 3-3 of FIG. 2;

FIG. 4 is a perspective view drawn to an enlarged scale of one of themagnetic segments of the device;

FIG. 5 is a rear view of the readout device as shown in FIG.

FIG. 6 is a vertical view of a section of the readout device drawn to anenlarged scale and taken in section in the plane of the line 3-3 of FIG.2, and depicting one phase of the operation thereof;

FIG. 7 is a view similar to FIG. 6 depicting a different phase of theoperation thereof;

FIG. 8 is a view similar to FIGS. 5 and ,6 and depicting a still furtherphase of the operation thereof;

FIG. 9 is a rear elevational view of the readout device shown in FIG. 1;and

FIG. 10 is a diagrammatic view of a modification showing how themagnetic segments may be used for an alpha-numeric type of readoutdevice.

Referring now more in detail to the drawings and having reference firstto FIG. 1 thereof, the segmental readout device of the inventioncomprises a readout unit generally designated as 10 mounted in a casing12 in which the unit is slidably received with a close fit, said casing,of rectangular cross section, being provided with a front opening 14closed by a clear glass window 16, the said casing having a rear end 18(shown more in detail in FIG. 9 of the drawings). The readout unit 10comprises an assembly of a plurality of closely spaced elongatedelectromagnetic coils 20,20 mounted and fixed to a front plate 22 madeof an insulating material and a rear plate 24 made of a ferrous metal,the front plate being provided with narrow elongated openings 26,26 inwhich cylindrical magnet elements 28,28 are mounted. FIG. 1 depicts thefront plate with the magnet segments mounted therein; and in FIGS. 2 and3 the readout unit is shown with the magnet segments removed from theelongated openings 26,26. The electromagnetic coils are each providedwith a core 30,30 made of a ferrous metal fixed in the front mountingplate 22 and the rear backing plate 24, the front 32 of each coreterminating at the elongated openings 26, as best shown in FIG. 3.

The magnet segments 28,28, as best shown in FIG. 1, are arranged to forma seven segment digital array of character exhibiting elements definingthe figure or numeral 8. Each magnet segment 28 is mounted for rotationin its opening 26 (acting as a socket opening) for rotation about itslongitudinal axis at an end of the core 30 associated therewith and alsofor a bodily movement to and from the saidcore, the movement beingbetween an end 32 of said core and the front glass window 16. This willbe best exemplified in connection with a later description of FIGS. 6 to8 of the drawings.

The structure of each magnet segment 28 is best depicted in FIG. 4 ofthe drawings, the same comprising a cylindrical ceramic magnetizedelement made of a magnetizable material such as barium ferrite bondedwith a suitable cement presenting a black surface 28 which is paintedwith a reflectively white coating 28 over one half of its cylindricalsurface, the said white coating providing a surface character to beexhibited in the operation of the readout device. This is illustratedbest in FIG. 1 of the drawings where four of these magnet segments havebeen rotated to a position where the white surfaces thereof are exposedin the readout display with the remaining magnet segments rotated to aposition where the black surfaces (28) thereof are in exposed positions,thereby effecting an assembled display, against the black background 22of the front mounting plate, of the numeral 4. As will be explainedlater, magnetization of each electromagnet 20 is effective to polarizeits core 30 to effect a bodily movement and a rotation of its relatedmagnet segment 28 between character exhibiting and non-exhibitingpositions. It will be understood that, as is common in readout devices,the seven segment digital array shown in FIG. 1 may be operated, bymeans hereinafter described, to exhibit any one of the digitalcharacters 0 to 9.

The readout unit 10 further comprises ferrous elements arranged inrelation to each core 30 and magnet segment 28 to provide a magneticflux return path for each said core and magnetic segment. The readoutdevice illustrated is a unit of small compass the dimensions of whichare 9/16 inch wide by inch high and 1 inch long. In a device of suchsmall dimen sions and embodying the digital array described, difficultyis experienced in eliminating the strays in the magnetic interactionbetween the separate cores and magnetic elements that is the cause offalse displays taking place. I have found that such a readout unit maybe designed and constructed with ferrous elements providing the fluxreturn paths so arranged that such magnetic strays and false displaysare entirely obviated. To the accomplishment of this end I provideelements for the return magnetic flux paths located inthe areas definedby the central spaces, i.e., within the two rectangles of the numeral orfigure 8 array, each of the two return magnetic paths serving as acommon return path for all of the magnetic segments which encompass acentral space or rectangle.

The elements thus provided for-this purpose comprise two elongatedferrous elements 34 and 36 mounted on and fixed to the front mountingplate 22 and the rear (ground) plate 24, one located in each centralspace area of the numeral 8, each provided at its front end with arectangular plate-like formation, 34 for the element 34 and 36' for theelement 36, these plate-like formations thus substantially filling thecentral space areas of the numeral 8 array. The surfaces of theseplate-like formations also provide a black background similar to thefront surface of the front plate 22. .The rear ends of the ferrouselements 34 and 36 are threaded to receive the nuts 38 and 40, theseserving to unite the parts of the readout device 10 into a firmassembled unit (10). As will be further explained below, each core 30and magnet 28 is thus provided with a flux return path in the parts ofone or the other of the ferrous elements 34, 36, including also theferrous material of the back plate 24.

The electrical and the magnetic circuits and the operation of elementsof the readout device are illustrated in FIGS. 6, 7 and 8 of thedrawings. The magnet segment 28 is permanently magnetized, this beingdesignated by the South and North poles S and N applied thereto in FIGS.6 to 8. The unmagnetized core 30 is magnetized when the electromagneticcoil 20 is operated. For setting and resetting the device, each coil 20is formed in two sections 20' and 20 the coil being provided withconductor a connected to one end of the coil section 20 the conductor bconnected to one end of the coil section 20 and a conductor connected toa midpoint of the coil 20. The conductor a of each coil is provided fora setting operation, the conductor b is rovided for a resettingoperation and the conductor c is connected to ground. The sevenconductors a, a of all of the electromagnets are individually connectedto seven terminals 42, 42 mounted on the back 18 of the casing (see FIG.9); the seven conductors b, b are unitedly connected as illustrated bythe connections b, b to the reset button 44 mounted on the back 18 ofthe casing; and all of the seven ground conductors c, c are similarlyunitedly connected to the ground terminal 46 mounted on the back 18 ofthe casing.

Upon closing the circuit to any of the setting buttons 42,42, and thusto any of the conductors a, a, its associated coil section 20 will beenergized to magnetize the associated core 30 in one direction with apolarity N-S such as is indicated in FIG. 8 of the drawings; and uponclosing the circuit to the reset button 44, and thus combinedly to allof the conductors b, b (12) their associated coils 20' will besimultaneously energized to magnetize the associated cores 30 in theopposite direction with a polarity S-N such as is indicated in FIG. 6 ofthe drawings. The magnetic circuits to provide the return magnetic fluxpaths are illustrated in FIGS. 6 to 8 by the magnetic circuitry thatconnects the topmost magnet 28 and its core 30 to its nearmost ferrouselement, namely element 34, this magnetic circuit being represented bythe encompassing dot-anddash lines 48 which embrace in sequence the core30, the magnetic element 28, the plate-like formation 34', the elongatedrod-like ferrous element 34 and the ferrous back plate 24. As notedabove, the ferrous return flux path combination 34' and 34 also servesas the return flux path for the other three magnet segments and theirassociated cores which form the top rectangle of the FIG. 8 array. Asalready noted each magnet segment 28 is arranged for free rotation inits elongated opening 26 and for bodily movement between the end 32 of acore and the front glass plate 16.

The operation of any of the magnetic segments for setting purposes andthe operation of all of them in unison for resetting purposes may now bedescribed in connection with FIGS. 6 to 8 of the drawings. Assuming thata magnet segment 28 by a previous operation has been positioned as shownin FIG. 6 of the drawings, with the black face 28 thereof in the exposeddisplay position, the closing of the circuit to a conductor a (viatemiinal 42) will energize the coil 20 and thereby magnetize the core 30to a polarity N-S as indicated in FIG. 7; and thereby the sequentialmovements illustrated in FIGS. 7 and 8 take place. The first of thesesequential movements is a bodily polar repulsion of the magnet segment28 toward the glass window 16 and a rotation by polar repulsion of themagnet segment in the direction indicated by the arrow 50 (FIG. 7); andthe second of these sequential movements is a bodily polar attraction ofthe magnet segment toward the core 30 and a continued rotation thereofby polar attraction, the magnet segment 28 coming to rest against theend 32 of the core 30 in the position depicted in FIG. 8. The magnetsegment at this point exhibits or displays the reflectively (visible)white coated face 28 thereof. The parts are held in this FIG. 8 positioneven after the circuit to the coil 20 is deenergized, the core 30 actingas a keeper for the magnet segment.

In this way any of the seven magnet segments or a combination of anumber thereof may be operated to produce any of the desired digitalcharacters. For the simultaneous return of all of the magnet segmenm,the circuit to the reset button 44 is closed, thereby energizing all ofthe coils 20, resulting in the return bodily and rotative movement ofall of the magnet segments 28 from the position illustrated in FIG. 8 tothe position illustrated in FIG. 6. Here again the parts are held intheir FIG. 6 position after the circuits to the coils 20' aredeenergized, the cores 30, 30 acting as keepers for the magnet segments28, 28.

As so far described the readout device has seven segments for thedisplay of digits. FIG. 10 shows a possible array of 14 segments, inwhich alphabetic as well as numeric characters may be displayed. Withthis modified structure it will be understood that there are 14 magneticsegments with 14 leads or connectors running to a suitable control orso-called logic box provided therefor.

The structure, operation, use and advantages of the readout device ofthis invention will, it is believed, be fully apparent from the abovedescription thereof. It will be further apparent that changes may bemade in the disclosed structure without departing from the spirit of theinvention defined by the following claims.

I claim:

I. A segmental readout device comprising an assembly of a plurality ofelongated electromagnetic coils closely arranged about a space commonthereto, each having a core of ferrous metal, a cylindrical magnetsegment, provided with a surface character to be exhibited, mounted forfree rotation about its longitudinal axis at an end of each core and forbodily movement to and from said core, magnetization of eachelectromagnet being effective to polarize its core to effect a bodilymovement and rotation of its related magnet segment between characterexhibiting and nonexhibiting positions, and a ferrous element arrangedin said space in relation to each core and magnet segment of theassembly to provide a common magnetic flux return path for all saidcores and magnet segments of the assembly.

2. The segmental readout device of claim 1 in which the magnet segmentsare arranged to form a seven segment digital array of characterexhibiting elements defining the figure or numeral 8, and in which theferrous elements providing the magnetic flux return path comprise twoferrous elements, one located in each center space area of the numeral8, and each serving as a common magnetic flux return path for all of themagnet segments and their related cores encompassing said center space.

3. The segmental readout device of claim 1, in which the electromagneticcoils, their ferrous cores and the ferrous elements are mounted on andfixed to a front insulating plate and a rear metallic plate, the frontplate being provided with narrow elongated openings in which thecylindrical magnet segments are mounted for said rotation and bodilymovement, the rear plate defining a ground plate for the ferrous coresand the ferrous elements.

4. The segmental readout device of claim 3 in which the elongatedopenings in the front plate and the magnet segments mounted therein arearranged to form a seven segment digital array defining the numeral 8and the electromagnets are arranged in a corresponding figure 8relation, and in which the ferrous elements providing the magnetic fluxreturn path comprise two members, each comprising a pan located in acentral space of the figure 8 and an elongated core connecting the sameto the rear metallic plate, and each serving as a common magnetic fluxreturn path for all the magnet segments and their related coresencompassing said center space.

5. A segmental readout device comprising an assembly of a plurality ofcoils closely arranged about a space common thereto, each coil having acore of ferrous metal, a magnet segment provided with a surfacecharacter to be exhibited mounted for free rotation at an end of eachcore, magnetization of each electromagnet being efiective to polarizeits core to effect a rotation of its related magnet segment betweencharacter exhibiting and non-exhibiting positions, and a ferrous elementin said space serving as a common magnetic flux return path for the saidplurality of cores and magnet segments of the assembly.

t I! I l

1. A segmental readout device comprising an assembly of a plurality ofelongated electromagnetic coils closely arranged about a space commonthereto, each having a core of ferrous metal, a cylindrical magnetsegment, provided with a surface character to be exhibited, mounted forfree rotation about its longitudinal axis at an end of each core and forbodily movement to and from said core, magnetization of eachelectromagnet being effective to polarize its core to effect a bodilymovement and rotation of its related magnet segment between characterexhibiting and nonexhibiting positions, and a ferrous element arrangedin said space in relation to each core and magnet segment of theassembly to provide a common magnetic flux return path for all saidcores and magnet segments of the assembly.
 2. The segmental readoutdevice of claim 1 in which the magnet segments are arranged to form aseven segment digital array of character exhibiting elements definingthe figure or numeral 8, and in which the ferrous elements providing themagnetic flux return path comprise two ferrous elements, one located ineach center space area of the numeral 8, and each serving as a commonmagnetic flux return path for all of the magnet segments and theirrelated cores encompassing said center space.
 3. The segmental readoutdevice of claim 1, in which the electromagnetic coils, their ferrouscores and the ferrous elements are mounted on and fixed to a frontinsulating plate and a rear metallic plate, the front plate beingprovided with narrow elongated openings in which the cylindrical magnetsegments are mounted for said rotation and bodily movement, the rearplate defining a ground plate for the ferrous cores and the ferrouselements.
 4. The segmental readout device of claim 3 in which theelongated openings in the front plate and the magnet segments mountedtherein are arranged to form a seven segment digital array defining thenumeral 8 and the electromagnets are arranged in a corresponding figure8 relation, and in which the ferrous elements providing the magneticflux return path comprise two members, each comprising a part located ina central space of the figure 8 and an elongated core connecting thesame to the rear metallic plate, and each serving as a common magneticflux return path for all the magnet segments and their related coresencompassing said center space.
 5. A segmental readout device comprisingan assembly of a plurality of coils closely arranged about a spacecommon thereto, each coil having a core of ferrous metal, a magnetsegment provided with a surface character to be exhibited mounted forfree rotation at an end of each core, magnetization of eachelectromagnet being effective to polarize its core to effect a rotationof its related magnet segment between character exhibiting andnon-exhibiting positions, and a ferrous element in said space serving asa common magnetic flux return path for the said plurality of cores andmagnet segments of the assembly.